1. Field of the Invention
The invention relates to a semiconductor device disposed with terminals for external connection.
2. Description of the Related Art
Liquid crystal displays (LCD) and plasma display panels (PDP), whose screen size is easy to enlarge, are currently gaining attention over displays using Braun tubes.
In these plasma display panels, high-voltage circuits and logic circuits that control the high-voltage circuits are disposed at output terminals of a PDP address driver integrated circuit (IC) inside a PDP module. Amplifier circuits are also disposed at input terminals of the PDP address driver IC. The addresses of the pixels of the plasma display are designated as a result of these circuits operating.
In order to reduce the manufacturing cost of the PDP module, the number of output terminals of a single PDP address driver IC is increasing and the number of parts inside the PDP module is being reduced. Specifically, the number of output terminals is being increased from 96 to 192 or 256. Further, in order to reduce the manufacturing cost of the PDP module, the PDP address driver IC is increasingly being mounted with respect to a tape carrier package (TCP) rather than a chip on flexible film (COF).
A technology has been proposed where the input terminals are arranged in one row on one edge portion of the PDP address driver IC, and where the output terminals are arranged in another row on the other edge portion of the PDP address driver IC (abbreviated below as “the one-row type”). FIG. 7 is a diagram showing a one-row type of PDP address driver IC.
In the one-row type, all of the input terminals 31 are disposed in one row on one edge portion, and all of the output portions 34 are disposed in another row on the other edge portion. Also, in the one-row type, a power supply potential is supplied from two power supply terminals 32 at both ends of a power supply wiring, and a ground potential is supplied from three ground terminals 33 at both ends and in the vicinity of the center of a ground wiring.
In the one-row type, when the PDP address driver IC is to be mounted with respect to a TCP, the terminals of the TCP are disposed in a direction parallel to the longitudinal direction of the PDP address driver IC. Thus, the length in the winding direction of the TCP becomes shorter and the manufacturing cost of the PDP module is reduced. Moreover, in the one-row type, even when the number of output terminals of the PDP address driver IC is increased and the routing of the wiring connecting elemental devices to elemental devices is lengthened, it is more difficult for the wiring resistance of the ground wiring to increase because the three ground terminals 33 are disposed with respect to the ground wiring. Thus, as it is harder for the wiring resistance to rise, it is harder for the ground potential to rise, and it is therefore more difficult for the PDP address driver IC to malfunction.
Another technology has also been proposed where the output terminals are disposed in two rows on one edge portion and on the other edge portion of the PDP address driver IC (abbreviated below as the “two-row type”). FIG. 8 is a diagram showing a two-row type of PDP address driver IC.
In the two-row type, all of input terminals 41 are disposed close together on one lateral-direction end of the PDP address driver IC, and output terminals 44x of output portions 44 are disposed in two rows on one edge portion and on the other edge portion. Also, in the two-row type, a power supply potential is supplied from two power supply terminals 42 at both ends of a power supply wiring, and a ground potential is supplied from two ground terminals 43 at both ends of a ground wiring.
In the two-row type, no gaps arise between the amplifier circuits in the vicinity of the input terminals 41 because the amplifier circuits connected to the input terminals 41 are arranged close together. Thus, the manufacturing costs of the PDP module and the PDP address driver IC are reduced because the chip size is reduced (see Gen Tada, Kazuhiro Kawamura and Masaru Saito, “PDP Address Driver IC Technology,” in Fuji Electric Journal, Vol. 76, No. 3 (2003), pp. 172-174). As an application of this type, there is also a three-row type of PDP address driver IC where the input terminals 44x are disposed in three rows (see Yoshihiro Shigeta and Gen Tada, “A Color Plasma Display Driver IC,” in Fuji Electric Journal, Vol. 69, No. 8 (1996), pp. 426-428).
However, in the one-row type, high-voltage circuits (under the power supply terminals 32 and the ground terminals 33) connected to output terminals 34x are disposed in the vicinity of the output terminals 34x, amplifier circuits connected to the input terminals 31 are disposed in the vicinity of the input terminals 31, and the high-voltage circuits operating at about 70 V are much larger than the amplifier circuits. For this reason, gaps arise between the amplifier circuits in the vicinity of the input terminals 31. Thus, the manufacturing costs of the PDP module and the PDP address driver IC are increased because the chip size is increased.
Also, in the two-row type and in a three-row type disclosed in the two aforementioned publications, when the PDP address driver IC is to be mounted with respect to a TCP, the terminals of the TCP are disposed in a direction perpendicular to the longitudinal direction of the PDP address driver IC. For this reason, the length in the winding direction of the TCP becomes longer, and the manufacturing cost of the PDP module increases. Moreover, in the two-row type and the three-row type, when the number of output terminals of the PDP address driver IC increases and the routing of the wiring connecting elemental devices to elemental devices becomes longer, it becomes easy for the wiring resistance of the ground wiring to rise because only the two ground terminals 43 are disposed with respect to the ground wiring. Thus, as it becomes easy for the wiring resistance to rise, it becomes easy for the ground potential to rise, and it becomes easy for the PDP address driver IC to malfunction.